The Constant Impedance Method for Measuring Inductance of Choke Coils

This paper describes a method for measuring at power frequencies the inductance of iron-cored choke coils of the type commonly used in radio as filters. It has been used to measure values of from one to more than 2000 henries. Two circuit arrangements are illustrated and several families of curves show how the inductance depends upon the magnitude of the superposed alternating and direct-current magnetomotive forces. The method may also be used at higher frequencies. It is simple, convenient to use, and requires the minimum of equipment.